/*

 * jchuff.h

 *

 * Copyright (C) 1991-1995, Thomas G. Lane.

 * This file is part of the Independent JPEG Group's software.

 * For conditions of distribution and use, see the accompanying README file.

 *

 * This file contains declarations for Huffman entropy encoding routines

 * that are shared between the sequential encoder (jchuff.c) and the

 * progressive encoder (jcphuff.c).  No other modules need to see these.

 */



/* Derived data constructed for each Huffman table */



typedef struct {

  unsigned int ehufco[256];	/* code for each symbol */

  char ehufsi[256];		/* length of code for each symbol */

  /* If no code has been allocated for a symbol S, ehufsi[S] contains 0 */

} c_derived_tbl;



/* Short forms of external names for systems with brain-damaged linkers. */



#ifdef NEED_SHORT_EXTERNAL_NAMES

#define jpeg_make_c_derived_tbl	jMkCDerived

#define jpeg_gen_optimal_table	jGenOptTbl

#endif /* NEED_SHORT_EXTERNAL_NAMES */



/* Expand a Huffman table definition into the derived format */

EXTERN void jpeg_make_c_derived_tbl JPP((j_compress_ptr cinfo,

				JHUFF_TBL * htbl, c_derived_tbl ** pdtbl));



/* Generate an optimal table definition given the specified counts */

EXTERN void jpeg_gen_optimal_table JPP((j_compress_ptr cinfo,

					JHUFF_TBL * htbl, long freq[]));

